I'm sorry I disagree with some of these answers. My rig is properly set up and you can get some sway with larger vehicles passing you. I have done the scales with just TT connected with and without the WDH and with the truck alone. My hitch weight is correct.
I have two Husky sway bars and have very little but SOME sway when larger vehicles pass. Not all, SOME. You are two units connected at a single point. The sway SHOULD NOT CONTINUE. The second sway bar made a hugh difference with my rig.
But I would do was the other posters tell you to do. Go to scales and get your rig weighed.